The impact of kidney donor profile index on delayed graft function and transplant outcomes: A single-center analysis

Body Mass Index and Kidney Donor Profile Index as Prognostic Markers of the Outcome of Renal Transplantation

BACKGROUND

The aim of this study was to determine the effects of Kidney Donor Profile Index (KDPI) and body mass index (BMI) of the deceased donor on the kidney allograft outcome 1 year after transplantation.

METHODS

We retrospectively studied 98 deceased kidney allograft donors with a mean age of 56 ± 12 years. The donors were divided into 5 groups according to their BMI: Normal ΒΜΙ = 25 (n = 25); ΒΜΙ 25 to 29 = Overweight (n = 33); ΒΜΙ 30 to 34.9 = Obese class I (n = 19); ΒΜΙ 35 to 39 = Obese class ΙΙ (n = 11); and ΒΜΙ >40 = Obese class III (n = 10). We examined the impact of the deceased donor's BMI and KDPI on delayed graft function (DGF) and estimated renal glomerular filtration rate (eGFR) (measured by the Chronic Kidney Disease Epidemiology Collaboration equation) 1 year after transplantation.

RESULTS

Donor BMI significantly increased the prevalence of DGF (P = .031), and it was associated with higher cold ischemia time (P = .021). However, there was no significant association between the aforementioned BMI groups and 1-year eGFR (P = 0.57), as deceased grafts from donors with increased BMI (BMI > 40) gained sufficient renal function during the first year of transplantation. Moreover, high KDPI was associated not only with DGF (P = .015), but also with decreased values of eGFR (P = .033).

CONCLUSION

In this population, we identified no significant association between donor BMI and long-term clinical outcomes in deceased donor kidney transplants. KDPI, and not ΒΜΙ, of the deceased donor seems to be a good prognostic factor of renal function at the end of the first year after kidney transplant, whereas high BMI and high KDPI markedly induce DGF.

Risk factors and outcomes for delayed kidney graft function in simultaneous heart and kidney transplant recipients: A UNOS/OPTN database analysis

There are no prior studies assessing the risk factors and outcomes for kidney delayed graft function (K-DGF) in simultaneous heart and kidney (SHK) transplant recipients. Using the OPTN/UNOS database, we sought to identify risk factors associated with the development of K-DGF in this unique population, as well as outcomes associated with K-DGF. A total of 1161 SHK transplanted between 1998 and 2018 were included in the analysis, of which 311 (27%) were in the K-DGF (+) group and 850 in the K-DGF (-) group. In the multivariable analysis, history of pretransplant dialysis (OR: 3.95; 95% CI: 2.94 to 5.29; p < .001) was significantly associated with the development of K-DGF, as was donor death from cerebrovascular accident and longer cold ischemia time of either organ. SHK recipients with K-DGF had increased mortality (HR: 1.99; 95% CI: 1.52 to 2.60; p < .001) and death censored kidney graft failure (HR: 3.51; 95% CI: 2.29 to 5.36; p < .001) in the multivariable analysis. Similar outcomes were obtained when limiting our study to 2008-2018. Similar to kidney-only recipients, K-DGF in SHK recipients is associated with worse outcomes. Careful matching of recipients and donors, as well as peri-operative management, may help reduce the risk of K-DGF and the associated detrimental effects.

Implementation of donation after circulatory death kidney transplantation can safely enlarge the donor pool: A systematic review and meta-analysis

BACKGROUND

Donation after circulatory death (DCD) kidney transplantation has been introduced to address organ shortage. However, DCD kidneys are not accepted worldwide due to concerns about inferior quality. To investigate whether these concerns are justified, we performed a systematic review and meta-analysis to investigate DCD graft outcomes compared to donation after brain death (DBD).

MATERIALS AND METHODS

EMBASE, Medline, Cochrane, Web of Science and Google Scholar were searched from database inception until September 2020. Exclusion criteria were studies reporting on pediatric/dual kidney transplants, multi-organ transplants or studies including normothermic perfusion techniques. The primary outcome was graft survival. Secondary outcomes were primary non-function (PNF), delayed graft function (DGF), 3-months biopsy-proven acute rejection (BPAR), 1-year estimated Glomerular Filtration Rate (eGFR), patient survival, and urologic complications. A random-effects model was used for meta-analysis. Meta-regression analysis was performed in case of high between-study heterogeneity.

RESULTS

Fifty-one studies were included, comprising 73,454 DCD and 518,229 DBD recipients. One-year graft loss was increased in DCD recipients (death-censored: risk ratio (RR) 1.10 (95%-confidence interval (CI) 1.04-1.16), all-cause: RR 1.13 (95%-CI 1.08-1.19)). Ten-year graft loss was similar to DBD (death-censored: RR 1.02 (95%-CI 0.92-1.13), all-cause: RR 1.03 (95%-CI 0.94-1.13)). DCD recipients had an increased risk of PNF (RR 1.43 (95%-CI 1.26-1.62)), DGF (RR 2.02 (95%-CI 1.88-2.16)), and 1-year mortality (RR 1.10 (95%-CI 1.01-1.21)). No differences were observed for 3-months BPAR, ureter stenosis/leakage, 1-year eGFR and 10-year mortality.

CONCLUSION

Long-term DCD kidney transplant outcomes are similar to DBD despite a higher risk of PNF, DGF, and a 13% increased risk of graft loss in the first year after transplantation. These results should encourage implementation of DCD programs.

Allograft nephrectomy versus nonallograft nephrectomy after failed renal transplantation: a systematic review by updated meta-analysis

There is limited evidence regarding the impact of allograft nephrectomy (AN) on the long-term outcome of subsequent kidney re-transplantation compared with no prior allograft nephrectomy. The aim of the present study was to conduct a systematic review and meta-analysis to estimate the accumulation of evidence over time. Primary outcomes were 5-year graft and patient survival. Cochrane library, Google scholar, PubMed, Medline and Embase were systematically searched. Meta-analysis was conducted using both fixed- and random-effects models. Study quality was assessed in duplicate using the Newcastle-Ottawa scale. Sixteen studies were included, with a total of 2256 patients. All included studies were retrospective and comparative. There was no significant difference in 5-year graft survival (GS) [Hazard Ratio (HR) = 1.11, 95% Confidence Intervals (CI): 0.89, 1.38, P = 0.37, I²  = 10%) or in 5-year patient survival (PS; HR = 0.70, 95% CI: 0.45, 1.10, P = 0.12, I²  = 0%]. Patients in the AN cohort were significantly younger than patients in the nonallograft nephrectomy (NAN) cohort by one year. Prior allograft nephrectomy was associated with a significantly higher risk of delayed graft function (DGF), acute rejection, primary nonfunction (PNF), per cent of panel reactive antibodies (% PRA) and allograft loss of the subsequent transplant. Although, DGF, % PRA, acute rejection and primary nonfunction rates were significantly higher in the AN cohort, allograft nephrectomy prior to re-transplantation had no significant association with five-year graft and patient survival.

Staggered Dual Kidney Transplantation

We describe a case where a patient received a successful dual kidney transplantation in a staggered fashion. Two kidneys from a deceased donor were accepted for 2 separate primary intended recipients, however, due to unforeseen circumstances, both kidneys were eventually transplanted in a staggered fashion into an alternate single recipient. The intention behind this method was to enhance the patient's renal function and to prevent the wastage of a kidney. Despite the significantly prolonged cold ischemia times, the recipient has excellent dual graft function after 3 years. The positive outcome underpins the effectiveness of donor kidneys even with prolonged cold ischemia times outside established best practice guidelines. It also reinforces the effectiveness of dual kidney transplantation. Transplant professionals encounter complex situations occasionally where an established evidence-base or aids to decision-making are limited. This case reflects challenges in decision-making, patient counselling and consent, especially when the opportunity for the staggered dual kidney transplantation, with potential increased morbidity, came about as another recipient declined a usable kidney. It also highlights the widely differing risk appetites of different patients. Crucially, it optimised the donation process and procurement of 2 kidneys while preventing wastage. To our knowledge, this is the first report of a staggered dual kidney transplantation in a single recipient.

Continuation of Peritoneal Dialysis in Adult Kidney Transplant Recipients With Delayed Graft Function

INTRODUCTION

Peritoneal dialysis (PD) has been used increasingly in past decade. Many of these patients undergo transplantation and may require dialysis for delayed graft function (DGF). The outcomes of DGF based on the post-transplantation dialysis modality are not well known.

METHODS

We retrospectively reviewed all adult kidney transplant recipients (KTRs) from the University of Wisconsin School of Medicine and Public Health who developed DGF between November 2015 and April 2019. Patients were divided into those who received hemodialysis (HD) or PD during the DGF period. Immediate graft explant, DGF among living donor KTRs, or those requiring just a single dialysis treatment were excluded.

RESULTS

Of 224 KTRs with DGF during the study period, 167 fulfilled our selection criteria. There were 16 patients in the PD and 151 in the HD group. Baseline characteristics were similar between the two groups, except diabetes was more prevalent in the HD group. Five of 16 PD patients had to be transitioned to HD. There was no difference in DGF duration, hospital length of stay, infectious or surgical complications, rejection at various time periods, graft function at last follow-up, or graft failure. In multivariate analysis, only rejection within the first year of transplantation (hazard ratio [HR]: 4.26; 95% confidence interval [CI]: 1.20-15.08; P = 0.02) and post-surgical complications (HR: 3.79; 95% CI: 1.03- 13.91; P = 0.04) were associated with death-censored graft failure (DCGF). The use of PD for treatment of DGF was not associated with DCGF.

CONCLUSIONS

In carefully selected patients, PD can be continued safely for DGF without any effect on short-term or long-term transplant outcomes.

Long Hemodialysis Duration Predicts Delayed Graft Function in Renal Transplant Recipients From Living Donor: A Single-Center Study

BACKGROUND

This study aims to determine the ratio of delayed graft function in renal transplant recipients from living donors and the predictive value of hemodialysis time before transplant for delayed graft function.

METHODS

We conducted a study on 116 adult patients who were diagnosed with end-stage kidney disease and were treated with hemodialysis and transplanted kidneys from living donors for 2 years (from June 2018 to June 2020). Delayed graft function event was collected for each patient.

RESULTS

The recipients had a median age of 36.5 years old, in which 55.2% of them were men, 4.3% of them had the diabetic mellitus, and the median hemodialysis duration was 6 months. The ratio of positive panel-reactive antibody was 33.6% and vascular reconstruction of the donor's kidney was 16.4%. The ratio of delayed graft function was 12.2% (14 of 116 patients). Delayed graft function significantly related to positive panel-reactive antibody, long duration of hemodialysis before transplant, and vascular reconstruction of donor's kidney with P < .001. Duration of hemodialysis before kidney transplant had a predictive value for delayed graft function (area under the curve, 0.83; P < .001).

CONCLUSION

Delayed graft function was not rare in renal transplant recipients from living donors. Duration of hemodialysis before kidney transplant was a good predictor for delayed graft function.

Recipient pre-existing chronic hypotension is associated with delayed graft function and inferior graft survival in kidney transplantation from elderly donors

BACKGROUND

Pre-existing chronic hypotension affects a percentage of kidney transplanted patients (KTs). Although a relationship with delayed graft function (DGF) has been hypothesized, available data are still scarce and inconclusive.

METHODS

A monocentric retrospective observational study was performed on 1127 consecutive KTs from brain death donors over 11 years (2003-2013), classified according to their pre-transplant Mean Blood Pressure (MBP) as hypotensive (MBP < 80 mmHg) or normal-hypertensive (MBP ≥ 80 mmHg, with or without effective antihypertensive therapy).

RESULTS

Univariate analysis showed that a pre-existing hypotension is associated to DGF occurrence (p<0.01; OR for KTs with MBP < 80 mmHg, 4.5; 95% confidence interval [CI], 2.7 to 7.5). Chronic hypotension remained a major predictive factor for DGF development in the logistic regression model adjusted for all DGF determinants. Adjunctive evaluations on paired grafts performed in two different recipients (one hypotensive and the other one normal-hypertensive) confirmed this assumption. Although graft survival was only associated with DGF but not with chronic hypotension in the overall population, stratification according to donor age revealed that death-censored graft survival was significantly lower in hypotensive patients who received a KT from >50 years old donor.

CONCLUSIONS

Our findings suggest that pre-existing recipient hypotension, and the subsequent hypotension-related DGF, could be considered a significant detrimental factor, especially when elderly donors are involved in the transplant procedure.

Acute Kidney Injury (AKI) before and after Kidney Transplantation: Causes, Medical Approach, and Implications for the Long-Term Outcomes

Acute kidney injury (AKI) is a common finding in kidney donors and recipients. AKI in kidney donor, which increases the risk of delayed graft function (DGF), may not by itself jeopardize the short- and long-term outcome of transplantation. However, some forms of AKI may induce graft rejection, fibrosis, and eventually graft dysfunction. Therefore, various strategies have been proposed to identify conditions at highest risk of AKI-induced DGF, that can be treated by targeting the donor, the recipient, or even the graft itself with the use of perfusion machines. AKI that occurs early post-transplant after a period of initial recovery of graft function may reflect serious and often occult systemic complications that may require prompt intervention to prevent graft loss. AKI that develops long after transplantation is often related to nephrotoxic drug reactions. In symptomatic patients, AKI is usually associated with various systemic medical complications and could represent a risk of mortality. Electronic systems have been developed to alert transplant physicians that AKI has occurred in a transplant recipient during long-term outpatient follow-up. Herein, we will review most recent understandings of pathophysiology, diagnosis, therapeutic approach, and short- and long-term consequences of AKI occurring in both the donor and in the kidney transplant recipient.

A prediction model of delayed graft function in deceased donor for renal transplant: a multi-center study from China

Background

Kidneys obtained from deceased donors increase the incidence of delayed graft function (DGF) after renal transplantation. Here we investigated the influence of the risk factors of donors with DGF, and developed a donor risk scoring system for DGF prediction.

Methods

This retrospective study was conducted in 1807 deceased kidney donors and 3599 recipients who received donor kidneys via transplants in 29 centers in China. We quantified DGF associations with donor clinical characteristics. A donor risk scoring system was developed and validated using an independent sample set.

Results

The incidence of DGF from donors was 19.0%. Six of the donor characteristics analyzed, i.e., age, cause of death, history of hypertension, terminal serum creatinine, persistence of hypotension, and cardiopulmonary resuscitation (CPR) time were risk factors for DGF. A 49-point scoring system of donor risk was established for DGF prediction and exhibited a superior degree of discrimination. External validation of DGF prediction revealed area under the receiver-operating characteristic (AUC) curves of 0.7552.

Conclusions

Our study determined the deceased donor risk factors related to DGF after renal transplantation pertinent to the Chinese cohort. The scoring system developed here had superior diagnostic significance and consistency and can be used by clinicians to make evidence-based decisions on the quality of kidneys from deceased donors and guide renal transplantation therapy.

Impact of donor obesity on allograft outcomes after kidney transplantation adjusted for kidney donor profile index - a national cohort study

Obesity in deceased kidney donors is a known risk factor for poor allograft outcomes. The Kidney Donor Profile Index (KDPI) has been introduced to predict graft survival in deceased donor kidney transplantation (DDKT). Obesity, however, is not included in KDPI. We study the impact of donor obesity on DDKT outcomes after adjusting for organ quality by KDPI. The Organ Procurement Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) data of DDKT from 2005 to 2017, with donor BMI ≥ 18.5 kg/m² and weight >80 kg were included. There was a total of 66 382 DDKTs with 10 917 death-censored graft failures. For KDPI ≤ 30%, the 10-year death-censored graft survival (DCGS) rates among donor BMI < 30, 30-35, 35-40, 40-45 and ≥45 kg/m² groups were 75.9%, 75.4%, 76.1%, 74.9% and 79.6%, respectively. For KDPI > 30%, 10-year DCGS rates were 67.5%, 66.1%, 65.9%, 62.6% and 63.2%, respectively. After adjusting for known confounding factors including KDPI, donor obesity was not independently associated with an increased risk for graft failure. In DDKT with donor weight >80 kg, donor obesity was not associated with a lower long term DCGS compared to non-obesity when KDPI ≤ 30%.

Impact of acute kidney injury in deceased donors with high Kidney Donor Profile Index on posttransplant clinical outcomes: a multicenter cohort study

BACKGROUND

This study evaluated the impact of acute kidney injury (AKI) on posttransplant clinical outcomes for deceased donor (DD) kidney transplantation (KT) using the Kidney Donor Profile Index (KDPI) system.

METHODS

Overall, 657 kidney transplant recipients (KTRs) receiving kidneys from 526 DDs from four transplant centers were included. We divided them into the high and low KDPI donor groups by 65%, the KDPI score, and both groups were subdivided into the AKI-DDKT and non-AKI-DDKT subgroups according to AKI in DDs.

RESULTS

There was no significant difference in the incidence of delayed graft function (DGF) between the high and low KDPI-KTR groups; however, the AKI-DDKT subgroup showed significantly higher incidence of DGF than the non-AKI-DDKT subgroup in both groups (p = 0.001, p < 0.001, respectively). The death-censored graft survival rate was significantly lower in the high KDPI-KTR group than in the low KDPI-KTR group (p = 0.005). Only in the high KDPI-KTR group, the death-censored graft survival rate was significantly lower in the KT from DDs with AKI stage 3 than KT from DDs with non-AKI or AKI stage 1 or 2 (p = 0.040). The interaction between AKI stage 3 in DDs and high KDPI on the allograft outcome was significant (p = 0.002).

CONCLUSION

KTs from DDs with AKI stage 3 showed an adverse impact on the allograft outcome in the high KDPI-KTR group. Therefore, DDs with a high KDPI score should be managed carefully so that severe AKI does not occur prior to KT.

Rate, Factors, and Outcome of Delayed Graft Function After Kidney Transplantation of Deceased Donors

BACKGROUND

Delayed graft function (DGF) is a frequent complication after kidney transplantation affecting long-term outcome.

PATIENTS AND METHODS

A total of 525 consecutive recipients (age 54.2 ± 13.4 years, 33% female) of kidneys from deceased donors transplanted between 2005 and 2012 were retrospectively examined. DGF was defined as the need of dialysis within the first week after transplantation.

RESULTS

DGF developed in 21.1% (n = 111). Factors associated with DGF (P ≤ .035, respectively) were recipient body mass index, C-reactive protein of the recipient, residual diuresis, cold ischemia time, donor age, and diuresis in the first hour after transplantation. Median duration of DGF was 16 (2-66) days. Patients after DGF had a significantly lower GFR compared with recipients without DGF either after 3 (32.9 ± 16.5 vs 46.3 ± 18.4 mL/min/1.73 m²) or after 12 months (38.9 ± 19.3 vs 48.6 ± 20.4 mL/min/1.73 m², P < .001, resp.). During DGF, 12.4% developed BANFF II and 18.0% BANFF I rejection, 20.2% had signs of transplant glomerulitis (first biopsy), and 16.2% (n = 18) remained on dialysis.

CONCLUSION

DGF affects 1 out of 5 kidney transplants from deceased donors. Minimizing modifiable risk factors, in particular immunologic risk, may ameliorate the incidence and outcome of DGF. The outcome of DGF depends mainly on the diagnosis of any rejection and worsens upon detection of transplant glomerulitis and pronounced interstitial fibrosis and tubular atrophy (IFTA).

Imaging in Renal Transplants: An Update

Renal transplantation has become the best treatment for the patients with chronic renal insufficiency. The surgical procedures, immunosuppressive regiments and patient follow-up have evolved especially in the last 10 years. However, the diagnosis for renal transplantation dysfunction remained the same in these years. Serum creatinine levels and estimated glomerular filtration rate calculated by serum creatinine based equations are used in routine patient follow-up. Pelvic ultrasonography and color Doppler ultrasonography are used as a first-line imaging method. Assessment of allograft functions both qualitatively and quantitatively are possible using nuclear medicine procedures. Surgical complications, acute tubular necrosis, subacute and/or acute rejection, infections, toxicity due to immunosuppressive medications, complications relating the collecting system, chronic rejection are the main causes for renal function impairment. The imaging procedures can diagnose the worsening of renal transplant function; however, they still lack the ability to differentiate types of rejection as histopathology or differentiate rejection from other causes of allograft dysfunction. The transplant biopsy gives detailed diagnosis for allograft dysfunction, guide the treatment and therefore it is the preferred diagnostic choice in recent years. On recent years, literature on radionuclide imaging is focused on perfusion analysis for the early diagnosis of renal transplant dysfunction and prognostic use of perfusion parameters, and then this article will focus on these studies and their outcome.

Urological Complications in Kidney Transplant Recipients: Analysis of the Risk Factors and Impact on Transplant Outcomes in the Era of “Extended Criteria Donors”

Urological complications (UC) following kidney transplantation (KT) are associated with increased morbidity. The aim of this study is to evaluate the risk factors for UC in the era of “extended criteria donors” (ECD) and their impact on patient and graft survivals. A retrospective monocentric study of all patients undergoing KT from 2010 to 2019 with a follow-up ≥30 days was performed. Out of 459 patients (males: 296 (64.5%); age: 57 (19–77) years) enrolled, 228 (49.7%) received ECD organs, moreover, 166 (67.2%) grafts had a cold ischemia time ≥10 h. UCs were reported in 32 (7%) patients. In 21 (65.6%) cases UC occurred within 3 months post-KT and 24 (5.2%) were associated with early urinary tract infection (UTI). The overall 5 year patient and graft survival rates were 96.5% and 90.6%, respectively. UC decreased graft survival (UC-group: 75.0% vs. noUC-group: 91.8%, p < 0.001), especially if associated with early UTI (UC-group: 71.4% vs. noUC-group: 77.8%, p < 0.001). At multivariate analysis, early UTI after KT (OR: 9.975, 95%-IC: 2.934–33.909, p < 0.001) and delayed graft function (DGF) (OR: 3.844, 95%-IC: 1.328–11.131, p: 0.013) were significant risk factors for UC, while ECD graft did not increase the risk of post-transplant UC. ECD grafts are not associated with UC. DGF and early UTI post-KT increase the risks of UC and reduce graft survival in the long-term. Therefore, aggressive management of early post-transplant UTI and strategies to reduce DGF incidence, such as machine preservation, are essential to prevent UC after KT.

Comprehensive assessment of deceased donor kidneys with clinical characteristics, pre-implant biopsy histopathology and hypothermic mechanical perfusion parameters is highly predictive of delayed graft function

Background: Due to the current high demand for transplant tissue, an increasing proportion of kidney donors are considered extended criteria donors, which results in a higher incidence of delayed graft function (DGF) in organ recipients. Therefore, it is important to fully investigate the risk factors of DGF, and establish a prediction system to assess donor kidney quality before transplantation.Methods: A total of 333 donation after cardiac death kidney transplant recipients were included in this retrospective study. Both univariate and multivariate analyses were used to analyze the risk factors of DGF occurrence. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of variables on DGF posttransplant.Results: The donor clinical scores, kidney histopathologic Remuzzi scores and hypothermic mechanical perfusion (HMP) parameters (flow and resistance index) were all correlated. 46 recipients developed DGF postoperatively, with an incidence of 13.8% (46/333). Multivariate logistic regression analysis of the kidney transplants revealed that the independent risk factors of DGF occurrence post-transplantation included donor score (OR = 1.12, 95% CI 1.06-1.19, p < 0.001), Remuzzi score (OR = 1.21, 95% CI 1.02-1.43, p = 0.029) and acute tubular injury (ATI) score (OR = 4.72, 95% CI 2.32-9.60, p < 0.001). Prediction of DGF with ROC curve showed that the area under the curve was increased to 0.89 when all variables (donor score, Remuzzi score, ATI score and HMP resistance index) were considered together.Conclusions: Combination of donor clinical information, kidney pre-implant histopathology and HMP parameters provide a more accurate prediction of DGF occurrence post-transplantation than any of the measures alone.

Predictors and one-year outcomes of patients with delayed graft function after deceased donor kidney transplantation

BACKGROUND

Delayed graft function (DGF) is closely associated with the use of marginal donated kidneys due to deficits during transplantation and in recipients. We aimed to predict the incidence of DGF and evaluate its effect on graft survival.

METHODS

This retrospective study on kidney transplantation was conducted from January 1, 2018, to December 31, 2019, at the Second Xiangya Hospital of Central South University. We classified recipients whose operations were performed in different years into training and validation cohorts and used data from the training cohort to analyze predictors of DGF. A nomogram was then constructed to predict the likelihood of DGF based on these predictors.

RESULTS

The incidence rate of DGF was 16.92%. Binary logistic regression analysis showed correlations between the incidence of DGF and cold ischemic time (CIT), warm ischemic time (WIT), terminal serum creatine (Scr) concentration, duration of pretransplant dialysis, primary cause of donor death, and usage of LifePort. The internal accuracy of the nomogram was 83.12%. One-year graft survival rates were 93.59 and 99.74%, respectively, for the groups with and without DGF (P < 0.05).

CONCLUSION

The nomogram established in this study showed good accuracy in predicting DGF after deceased donor kidney transplantation; additionally, DGF decreased one-year graft survival.

African American polycystic kidney patients receive higher risk kidneys, but do not face increased risk for graft failure or post-transplant mortality

African Americans (AA) are disproportionately affected by end-stage renal disease (ESRD) and have worse outcomes following renal transplantation. Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic condition leading to ESRD necessitating transplant. We explored this population with respect to race by conducting a retrospective analysis of the UNOS database between 2005 and 2019. Our study included 10,842 (AA n = 1661; non-AA n = 9181) transplant recipients whose primary diagnosis was ADPKD. We further stratified the AA ADPKD population with respect to blood groups (AA blood type B n = 295 vs AA non-B blood type n = 1366), and also compared this cohort to AAs with a diagnosis of DM (n = 16,706) to identify unique trends in the ADPKD population. We analyzed recipient and donor characteristics, generated survival curves, and conducted multivariate analyses. African American ADPKD patients waited longer for transplants (924 days vs 747 days P < .001), and were more likely to be on dialysis (76% vs 62%; p < .001). This same group was also more likely to have AA donors (21% vs 9%; p < .001) and marginally higher KDPI kidneys (0.48 vs 0.45; p < .001). AA race was a risk factor for delayed graft function (DGF), increasing the chance of DGF by 45% (OR 1.45 95% CI 1.26-1.67; p < .001). AA race was not associated with graft failure (HR 1.10 95% CI 0.95-1.28; p = .21) or patient mortality (HR 0.84 95% CI 0.69-1.03; p = .09). Racial disparities exist in the ADPKD population. They should be continually studied and addressed to improve transplant equity.

Modeling the economic benefit of targeted mild hypothermia in deceased donor kidney transplantation

Delayed graft function (DGF) in kidney transplant significantly increases inpatient and outpatient cost. Targeted, mild hypothermia in organ donors after neurologic determination of death significantly reduced the rate of DGF in a recent randomized controlled clinical trial. To assess the potential economic benefit of national implementation of donor hypothermia, rates of reduction DGF were combined with estimates of the impact of DGF on hospital cost and total health expenditure for standard and extended criteria donor organs (SCD and ECD). DGF increases the cost of the transplant episode by $9487 for ECD transplant and $10 342 for SCD transplant. Medicare recipients with DGF incur an additional $18 513 spending for ECD and $14 948 in SCD transplants over the first year. An absolute reduction in DGF rate after kidney transplantation consistent with trial results (ECD 25%, SCD 7%) has the potential to lower annual hospital cost for kidney transplant by $13 178 746 and annual Medicare spending by $20 970 706 compared to standard donor management practice using static cold storage. Targeted mild hypothermia improves care of renal transplant patients by safely reducing DGF rates in both ECD and SCD transplant. Broader application of this safe, effective, and low-cost intervention could reduce healthcare expenditures for providers and insurers.

Relevance of KDPI value and acute rejection on kidney transplant outcomes in recipients with delayed graft function - a retrospective study

Delayed graft function (DGF) is associated with poorer graft survival and higher rate of acute rejection (AR). It is unknown whether this negative influence relies on the increased risk of AR or the DGF itself. The different Kidney Donor Profile Index (KDPI) values may also play a role in this interaction. Retrospective study aimed to evaluate the impact of DGF on graft function and graft survival in a subset of KT recipients (2004-2017). We also analyzed the relationship between KDPI and DGF. The study includes 601 KT, 226 of them (37%) developed DGF. Graft survival was lower in patients with DGF compared with non-DGF patients. Multivariable analysis revealed DGF as risk factor for graft loss, independently of the presence or not of acute rejection. Between DGF patients, we observed poorer graft survival in patients with higher KDPI value (>85%). We observed a trend of a greater impact of KDPI in patients with DGF, although this interaction was not statistically significant. Additionally, we observed poorer 12-month graft function in DGF patients. DGF is related to poorer graft survival independently of the developed acute rejection. This negative impact might be influenced by high KDPI values.

Donor Age, Cold Ischemia Time, and Delayed Graft Function

BACKGROUND AND OBJECTIVES

Increased donor age is one of the most important risk factors for delayed graft function (DGF), and previous studies suggest that the harmful effect of cold ischemia time is increased in kidneys from older donors. Our aim was to study the association of increased donor age and cold ischemia time with the risk of delayed graft function in a large cohort kidney transplants from the current era.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Scientific Registry of Transplant Recipients was used for this observational, retrospective registry analysis to identify all deceased donor kidney transplantations in the United States between 2010 and September 2018, who were on dialysis pretransplantation (n=90,810). The association of donor age and cold ischemia time with the risk of DGF was analyzed in multivariable models adjusted for recipient characteristics (age, race, sex, diabetes, calculated panel-reactive antibodies, pretransplant dialysis duration) and donor characteristics (cause of death, sex, race, body mass index, creatinine, donation after circulatory death status, history of hypertension, and HLA mismatch).

RESULTS

Cold ischemia time and donor age were independently associated with the risk of DGF, but the risk of DGF was not statistically significantly lower in donor age categories between 50 and 64 years, compared with donors ≥65 years. The harmful association of cold ischemia time was not higher in kidneys from older donors in any age category, not even among donation after circulatory death donors. When donor risk was assessed with kidney donor profile index, although a statistically significant interaction with cold ischemia time was found, no practically meaningful increase in cold-ischemia susceptibility of kidneys with a high kidney donor profile index was found.

CONCLUSIONS

We were unable to demonstrate an association between donor age and DGF. The association of longer cold ischemia time with the risk of DGF was not magnified in older or more marginal donors.

Dynamic 2-deoxy-2[18F] fluoro-D-glucose PET/MRI in human renal allotransplant patients undergoing acute kidney injury

Patients after solid organ kidney transplantation (KTX) often suffer from acute kidney injury (AKI). Parameters as serum creatinine indicate a loss of kidney function, although no distinction of the cause and prognosis can be made. Imaging tools measuring kidney function have not been widely in clinical use. In this observational study we evaluated 2-deoxy-2[18F] fluoro-D-glucose (FDG) PET/MRI in thirteen patients after KTX with AKI as a functional assessment of the graft. Twenty-four healthy volunteers served as control. General kidney performance (GKP), initial flow (IF) and renal response function (RF) were calculated by standardized uptake values (SUV) and time activity curves (TAC). The GKP measured for the total kidney and medulla was significantly higher in healthy patients compared to patients after KTX (p = 0.0002 and p = 0.0004, respectively), but no difference was found for the GKP of the cortex (p = 0.59). The IF in KTX patients correlated with renal recovery, defined as change in serum creatinine 10 days after PET/MRI (r = 0.80, p = 0.001). With regard to the RF, a negative correlation for tubular damage was found (r = -0.74, p = 0.004). In conclusion, parameters obtained from FDG PET/MRI showed a possible predictive feature for renal recovery in KTX patients undergoing AKI.

Degree of Glomerulosclerosis in Procurement Kidney Biopsies from Marginal Donor Kidneys and Their Implications in Predicting Graft Outcomes

Background: This study aimed to assess the association between the percentage of glomerulosclerosis (GS) in procurement allograft biopsies from high-risk deceased donor and graft outcomes in kidney transplant recipients. Methods: The UNOS database was used to identify deceased-donor kidneys with a kidney donor profile index (KDPI) score > 85% from 2005 to 2014. Deceased donor kidneys were categorized based on the percentage of GS: 0-10%, 11-20%, >20% and no biopsy performed. The outcome included death-censored graft survival, patient survival, rate of delayed graft function, and 1-year acute rejection. Results: Of 22,006 kidneys, 91.2% were biopsied showing 0-10% GS (58.0%), 11-20% GS (13.5%), >20% GS (19.7%); 8.8% were not biopsied. The rate of kidney discard was 48.5%; 33.6% in 0-10% GS, 68.9% in 11-20% GS, and 77.4% in >20% GS. 49.8% of kidneys were discarded in those that were not biopsied. Death-censored graft survival at 5 years was 75.8% for 0-10% GS, 70.9% for >10% GS, and 74.8% for the no biopsy group. Among kidneys with >10% GS, there was no significant difference in death-censored graft survival between 11-20% GS and >20% GS. Recipients with >10% GS had an increased risk of graft failure (HR = 1.27, p < 0.001), compared with 0-10% GS. There was no significant difference in patient survival, acute rejection at 1-year, and delayed graft function between 0% and 10% GS and >10% GS. Conclusion: In >85% KDPI kidneys, our study suggested that discard rates increased with higher percentages of GS, and GS >10% is an independent prognostic factor for graft failure. Due to organ shortage, future studies are needed to identify strategies to use these marginal kidneys safely and improve outcomes.

Assessment of Organ Quality in Kidney Transplantation by Molecular Analysis and Why It May Not Have Been Achieved, Yet

Donor organ shortage, growing waiting lists and substantial organ discard rates are key problems in transplantation. The critical importance of organ quality in determining long-term function is becoming increasingly clear. However, organ quality is difficult to predict. The lack of good measures of organ quality is a serious challenge in terms of acceptance and allocation of an organ. The underlying review summarizes currently available methods used to assess donor organ quality such as histopathology, clinical scores and machine perfusion characteristics with special focus on molecular analyses of kidney quality. The majority of studies testing molecular markers of organ quality focused on identifying organs at risk for delayed graft function, yet without prediction of long-term graft outcome. Recently, interest has emerged in looking for molecular markers associated with biological age to predict organ quality. However, molecular gene sets have not entered the clinical routine or impacted discard rates so far. The current review critically discusses the potential reasons why clinically applicable molecular quality assessment using early kidney biopsies might not have been achieved yet. Besides a critical analysis of the inherent limitations of surrogate markers used for organ quality, i.e., delayed graft function, the intrinsic methodological limitations of studies assessing organ quality will be discussed. These comprise the multitude of unpredictable hits as well as lack of markers of nephron mass, functional reserve and regenerative capacity.

The management of lower limb arteriovenous grafts in the perioperative period following renal transplantation

BACKGROUND

The presence of a lower limb arteriovenous graft (LL-AVG) is indicative of a group of complex hemodialysis patients who have precarious long-term vascular access. The aim of this study is to describe our experience of the clinical decisions and interactions between LL-AVG and renal transplantation.

METHODS

The records of 23 patients who received a transplant in the presence of a LL-AVG between 2010 and 2018 were analyzed: firstly, to determine whether patients with a LL-AVG received extended criteria transplants, the implantation procedure, and the management of the LL-AVG in the post-operative period.

RESULTS

Seventeen patients (74%) had "end-stage access" and were thus considered for all offer stratified by the kidney donor profile index (KDPI) and donor type (DBD or DCD). In eleven patients (48%), a kidney with a high risk of delayed graft function was transplanted. Same-sided renal transplantation occurred in only 35% of cases, and of these, only one LL-AVG was ligated immediately to improve transplant perfusion.

CONCLUSION

A patient-based approach applied in decision-making on management of the LL-AVG post-transplantation should include (a) the likelihood of delayed graft function, (b) the need for post-operative hemodialysis, (c) the side of proposed transplant compared to the LL-AVG, and (d) local complications.

Marginal kidney transplantation: the road less traveled

PURPOSE OF REVIEW

Kidney transplantation indisputably confers a significant survival advantage and a better quality of life compared with dialysis, however, because of the increasing demand for kidney transplantation many patients continue to wait prolonged periods for kidney transplantation. The first step to alleviate the shortage is to reduce the discard rate by utilizing more marginal kidneys. This review studied the recent literature on marginal kidney transplantation.

RECENT FINDINGS

More than 60% of high-KDPI kidneys are discarded. Despite the increase in posttransplant costs, use of high KDPI transplants suggests a gain in survival years, thus making marginal kidney transplant cost effective. Furthermore, recent evidence suggests that marginal kidney transplantation shows a survival benefit compared with remaining in the waitlist and minimizes the kidney discard rate.

SUMMARY

Transplantation with marginal kidneys provides a survival benefit over dialysis or waiting for a low-KDPI kidney. As a result, clinicians should strongly consider transplantation of marginal kidneys as opposed to waiting for a better offer.

Systematic Surgical Assessment of Deceased-Donor Kidneys as a Predictor of Short-Term Transplant Outcomes

BACKGROUND

Short-term kidney graft dysfunction is correlated with complications and it is associated with a decreased long-term survival; therefore, a scoring system to predict short-term renal transplant outcomes is warranted.

AIM

The aim of this study is to quantify the impression of the organ procurement surgeon in correlation with the following kidney transplant outcomes: immediate graft function (IGF), delayed graft function (DGF), and primary nonfunction (PNF). Results are compared to factors associated with the 1-year outcome.

METHODS

A regional prospective pilot study was performed using deceased-donor organ assessment forms to be filled out by procurement surgeons after procurement. Data were gathered on kidney temperature, perfusion, anatomy, atherosclerosis, and overall quality.

RESULTS

Included were 90 donors who donated 178 kidneys, 166 of which were transplanted. Variables that were significantly more prevalent in the DGF-or-PNF group (n = 65) are: large kidney size (length, p = 0.008; width, p = 0.036), poor perfusion quality (p = 0.037), lower diuresis (p = 0.039), fewer hypotensive episodes (p = 0.003), and donation-after-circulatory-death donors (p = 0.017). Multivariable analysis showed that perfusion quality and kidney width significantly predicted the short-term outcome. However multivariable analysis of long-term outcomes showed that the first measured donor creatinine, kidney donor risk index, IGF vs. DGF+PNG, and kidney length predicted outcomes.

CONCLUSIONS

Results show that short-term graft function and 1-year graft function indeed are influenced by different variables. DGF and PNF occur more frequently in kidneys with poor perfusion and in larger kidneys. A plausible explanation for this is that these kidneys might be insufficiently washed out, or even congested, which may predispose to DGF. These kidneys would probably benefit most from reconditioning strategies, such as machine perfusion. A scoring system including these variables might aid in decision-making towards allocation and potential reconditioning strategies.

Blessing and a curse of outpatient management of delayed graft function

Delayed graft function (DGF) is a common complication occurring most often after deceased donor kidney transplant with several donor characteristics as well as immunologic factors that lead to its development post-transplant. These patients require dialysis and close kidney function monitoring until sufficient allograft function is achieved. This has resulted in limited options for DGF management, either prolonged hospitalization until graft function improves to the point where dialysis is no longer needed or discharge back to their home dialysis unit with periodic follow up in the transplant clinic. DGF is associated with a higher risk for acute rejection, premature graft failure, and 30-d readmission; therefore, these patients need close monitoring, immunosuppression management, and prompt allograft biopsy if prolonged DGF is observed. This may not occur if these patients are discharged back to their home dialysis unit. To address this issue, the University of Wisconsin-Madison created a clinic in 2011 specialized in outpatient DGF management. This clinic was able to successfully reduce hospital length of stay without an increase in 30-d readmission, graft loss, and patient death.

SLPI in the perfusion solution helps to identify graft quality in kidney transplants

Aim: It is important to find biomarkers that identify the graft quality in kidney transplantation. Results & methodology: The level of SLPI in the cold preservation solution was used as a marker to predict early kidney graft function after transplantation. Before transplantation, kidneys were washed and SLPI was measured in the discarded solution. A retrospective analysis showed that patients with delayed graft function or rejection episodes in post-trasplant, had higher SLPI concentrations in the perfusion solution than patients without delayed graft function or rejections. Furthermore, SLPI could discriminate between patients with better or worse estimated glomerular filtration rate among low-risk patients (kidney donor profile index <80). Discussion & conclusion: These results suggest that the SLPI concentration in the perfusion solutions could be a predictor of short-term organ function and a complement to the kidney donor profile index score.

Improved long-term outcomes after heart transplantation utilizing donors with a traumatic mode of brain death

Background

The donor’s mode of brain death (BD), being associated with impairment of myocardial function and hemodynamic performance, impacts the prognosis of the heart transplantation (HTx) recipient.

Methods

All patients who underwent HTx between 1996 and 2017 were categorized according to donor’s BD mechanism: traumatic BD (TBD) versus non-traumatic BD (NTBD).

Results

The TBD group included 105 recipients, and the NTBD group, 85 recipients. Kaplan-Meier survival analysis showed that overall survival was significantly higher for recipients of TBD hearts (10-year survival 58.1 vs. 37.6%, p = 0.044). Consistently, multivariate analysis showed that TBD was independently associated with a significant 43% reduction in mortality [95% confidence interval (CI) 0.42–0.75, p = 0.033]. Rejection rate was lower in the TBD group (total rejection score 0.44 ± 0.32 vs. 0.51 ± 0.38, p = 0.04; any rejection score 0.38 ± 0.26 vs. 0.45 ± 0.31, p = 0.030), and freedom from cardiac allograft vasculopathy (CAV) was significantly higher in recipients of traumatic vs. non-traumatic donors (10 years: 82.9 vs. 62.4%, log-rank p-value = 0.024). Multivariate analysis showed a significant 42% reduction in CAV [hazard ratio (HR) = 0.58, 95% CI 0.51–0.85, p = 0.022).

Conclusion

Mode of brain death significantly impacts HTx outcomes, with TBD being associated with reduced mortality, rejections and CAV.

The Impact of Therapeutic Hypothermia Used to Treat Anoxic Brain Injury After Cardiopulmonary Resuscitation on Organ Donation Outcomes

Therapeutic hypothermia (TH) is clinically used to improve neurologic outcomes in patients with anoxic brain injury after cardiopulmonary resuscitation (CPR). For patients that regress and become organ donors after neurologic determination of death (DNDDs), the impact of TH received before determination of death on organ donation outcomes remains unknown. A prospective observational study of all adult DNDDs that received CPR and had anoxia as a cause of death from March 2013 to December 2014 was conducted across 20 organ procurement organizations (OPOs) in the United States. Main outcome measures included organs transplanted per donor (OTPD), specific organ transplantation rates, and recipient graft outcomes. One thousand ninety eight DNDDs met inclusion criteria, with 46% having received TH before determination of death. DNDDs with hypothermia before death had a similar number of OTPD (2.74 vs. 2.69, p = 0.61) and similar transplantation rates of individual organs. With regards to recipients, there was significantly less delayed graft function (DGF) in kidney grafts from donors who received TH before death (24% vs. 30%, p = 0.02). After adjusting for donor, recipient, and graft related factors, the protective effect of TH on DGF persisted (OR 0.75, 95%CI [0.56-0.995], p = 0.046). TH before death in the donor is independently associated with a 25% decrease in DGF among kidney recipients. This should be considered a protective donor selection factor in guiding the decision to accept or reject an organ for transplantation.

Burden of excess mortality after implementation of the new kidney allocation system may be borne disproportionately by middle-aged recipients

Under the new kidney allocation system (KAS), implemented in 2014, the distribution of the best quality donor kidney grafts shifted between age groups, but it is unclear whether this change translates to meaningful differences in post-transplant outcomes. We conducted a retrospective cohort study of 20,345 deceased donor kidney transplant recipients before and 4,605 recipients after implementation of the KAS using data from the United Network of Organ Sharing. Overall, two-year mortality was greater among recipients in the post-KAS era compared with the pre-KAS era (6.31% vs 5.91% respectively, [p = 0.01]), and two-year graft loss was not significantly different between eras (9.95% and 9.65%, respectively [p = 0.13]). In analysis stratified by age group (18-45, 46-55, 56-65, and ≥66 years), relative risk of mortality was 1.48 (95% confidence interval [CI] 1.09-1.98) among recipients 46-55 years old and 1.47 (95% CI 1.18-1.81) among recipients 56-65 years old. Relative risk of all-cause graft loss was 1.43 (95% CI 1.20-1.70) among recipients 56-65 years old. There were no significant differences in relative risk of mortality or graft loss associated with the KAS era among other age groups. After adjustment for recipient characteristics and characteristics of the changing donor pool, relative risk of two-year mortality and graft loss associated with the post-KAS era was attenuated for recipients aged 46-55 and 56-65 years, but remained statistically significant. In this early analysis after implementation of the KAS, there is suggestion that increased risk of mortality and graft loss may be disproportionately borne by middle-aged recipients, which is only partially accounted for by changes in recipient and donor characteristics. These findings signal a need to continue to monitor the effects of the KAS to ensure that allocation practices both maximize utility of the kidney graft pool and respect fairness between age groups.

Delayed Graft Function: The AKI of Kidney Transplantation

With the growing wait list of individuals waiting for kidney transplantation, there has been renewed interest in the quality and function of donor organs. In particular, concern about the development of delayed allograft function (DGF) after transplantation continues to lead to the avoidance of donor organs offered to a transplant center. DGF is associated with worse short-and long-term outcomes and associated with higher rejection rates. There are no FDA-approved therapies to mitigate the ischemic injury that occurs. Risk factors include both donor and recipient characteristics, although their prediction is not precise. With new understanding about mechanisms of injury and new focus on the function of the deceased donor, there is opportunity to identify not only novel therapies to improve allograft function but to identify potential biomarkers of DGF. DGF remains a significant factor in impacting kidney transplant outcome, and finding biomarkers will assist in the development and approval of novel agents to ameliorate early and later injury. This mini-review highlights our presentation at the 23rd International Conference on Advances in Critical Care Nephrology and UAB/UCSD O'Brien Center Acute Kidney Injury (AKI) Pre-Meeting.